Certain known fuel pressure regulators do not axially capture associated O-ring seals, and as a consequence, it is possible for the seals to become accidentally separated from the fuel pressure regulator when it is removed from its fuel rail. It is therefore preferable for the seals to be axially captured on a fuel pressure regulator so that they do not become accidentally separated, and certain other fuel pressure regulators are constructed to axially capture the associated O-rings seals so that the O-rings stay on the fuel pressure regulator when it is removed from its fuel rail.
One known fuel pressure regulator that captures its O-rings comprises a multiple part housing, consisting of one stamping and two screw-machined parts, and requiring brazing and crimping operations in its manufacture. It has a brazed joint that must be completely leak-proof. To assure quality in a mass-production setting, the brazed joint of each valve must be pressure-tested, and because of the nature of the mass-production process, not all valves will be found to have completely leak-proof brazed joints. The use of a brazed joint, the necessity for pressure-testing it, and the improbability of obtaining a completely leak-proof brazed joint in every fuel pressure regulator makes that design relatively expensive. Moreover, that fuel pressure regulator does not integrate the filter screen because it uses a separate plastic filter element.
Commonly assigned U.S. Pat. No. 5,076,320 discloses a fuel pressure regulator having captured O-ring seals and a filter screen. Another patent relating to a fuel pressure regulator is U.S. Pat. No. 4,883,088. The latter has a plastic filter screen that is fitted onto the outside of the fuel pressure regulator.
The present invention relates to an improved fuel pressure regulator having an integral filter screen and captured O-ring seals. The fuel pressure regulator of the present invention is an improvement because of the new and unique means for integrating the filter screen and axially capturing one of two O-rings seals. The invention comprises the use of only a crimp and a shoulder on the outlet tube to unite the outlet tube, the fuel pressure regulator housing, and a washer that in one embodiment performs both the function of sandwiching the filter screen between itself and the wall of the housing through which the outlet tube passes and the function of cooperating with the housing in defining the groove which captures one of the two O-ring seals. The fuel enters the fuel pressure regulator via overlapping through-holes in the washer and the housing wall between which the filter screen is disposed so that only filtered fuel actually enters the fuel pressure regulator housing. In another embodiment the filter screen is attached to the exterior of the washer in covering relation to the overlapping through-holes. The invention offers meaningful improvements in both manufacturing and cost.
The foregoing, along with additional features, advantages, and benefits of the invention, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a presently preferred embodiment of the invention according to the best mode contemplated at this time for carrying out the invention.